 2.15 (see [1]}) Let \((A,\mathfrak {m})\)  be a Noetherian local ring and \(M\)  a Cohen-Macaulay \(A\) -module with dim\(M=1\) . Let \(x\)  be an \(M\) -superficial element. Set \(\rho _n(M)=\ell (\mathfrak {m}^{n+1}M/x\mathfrak {m}^nM)\)  for all \(n\ge 0\) . If deg\(h_M(z)=s\)  then
